Monday, June 04, 2007

Road Systems

One thing that continually amazes me out here in Minneapolis is how well-organized the road system is. As you can see above this paragraph, I've given you a fairly good birds-eye view of the Twin Cities' highway system. Given that there are two cities within the metropolitan region, it's particularly interesting to see how planners have, over the years, decided to route traffic.

Let's start by reviewing some of the high points of the system:

The region is ringed by a complete beltway. This means that no matter where you are in the inner-ring and middle-ring suburbs, you can count on being within ten or so minutes of interstate access. Contrast this, for example, with Richmond (VA), which last time I checked had only a 75% beltway system (quadrants 2, 3, and 4 I believe). The incomplete beltway is a hassle--if you're at one end of the beltway and you want to get to the other, you have to go all the way around (a trip three times longer than necessary!).

Excellent secondary arterials! I've written about this one before. By secondary arterial, I mean roads with at least 35 mph speed limits and little to no traffic lights or stop signs. People often overlook these roads in evaluating the quality of a road system; they instead look to formal highways to assess how easy it is to get around. They miss, however, the fact that even though these secondary quasi-highways are slower (even 35 mph, as I said), the small number of traffic lights makes them very efficient for travel. Some examples include: Route 55, Snelling Ave., and many of the north-south avenues on the southside of Minneapolis (Portland, Nicollet, for example).

Controlled highway access: many highway on-ramps feature gated access. If you've never seen this, here's what it looks like: a normal on-ramp, only there are traffic lights halfway down the ramp on either side. Normally, these lights stay on blinking yellow. In rush-hour, they switch to alternating red/green to allow two lanes of on-ramp traffic to take turns merging. It effectively reduces the vehicle load on the actual highway by shifting it to the ramps themselves. While it's not a total solution to under-capacity, it minimizes bumper-to-bumper slowdowns on the highways themselves.

5 Comments:

Like me, you will probably grow to loathe and despise many aspects of our freeway system.

I shouldn't make a blanket statement, I guess. The roads themselves are well-engineered. It's the idiots on them that will make you insane.

My favorite folks are SUV drivers in bumper-to-bumper, 5 MPH traffic. It doesn't matter that everyone is slowed to a crawl. What matters is that THEY'RE slowed to a crawl...IN FRONT OF YOU. 2-second rule be damned.

Yeah. I'm glad you posted this. Having lived in other cities I must admit the Twin Cities is fairly easy to get around in. Sure we have traffic, but have you tried to drive in Chicago or Boston? I'll take a little slow down on 94 any day.

While I agree with you for the most part, there are still some frustrating issues with the freeway system as it stands. Two in particular that impact me more often than I would like are 1) trying to get to Downtown St Paul from NE Minneapolis involves convoluted trips through interesting surface streets to get to either 94E or 280S and 2) access to East and Southbound freeways from Howe and Longfellow neighborhoods in South Minneapolis requiring similar, though much more intuitive surface street detours, to the previous example.

I wonder what factors allow for a successful grid system? My guess includes topography, scale, and good planning. Flatter areas are easier to pave; so that's intuitive. The Twin Cities are large, but not huge like D.C. -- where there is not a grid system save for the area immediately around Capitol Hill -- and thus more maneageble. Good planning is essential of course. History plays a role, too. It seems "newer" American cities have benefited as have European cities that were bombed. They got a new chance to "reenvisioned" themselves with modern transport needs in mind.

Now about those pesky SUV drivers... Two words, baby, Mack Truck. Who is the real king of the Circus Maximus? That's what I thought, respect ... Case dismissed...

Having driven in Chicago, I'll take the Twins any day. The move from the Minneapolis side of the river to the St. Paul said has cut my commute time considerably. I am amazed at the disorganization of side streets in St. Paul where the switch to the next hundred in house numbers may take 3-4 blocks and the named streets are not numbered. However, St. Paul has Ayd Mill Road, Shepard Rd., Energy Park Drive, Pierce Butler, the Phalen Corridor, etc., that have limited stops and allow higher speed limits. Now that I have discovered those speedier short cuts, I rarely use the highway system. Even getting to "Nordeast" is easier once you've discovered the parkways!